The present invention relates to a semiconductor device, and, for example, to a technology applicable to a semiconductor device having a memory.
As a memory for achieving a high-speed operation, a magnetic random access memory (MRAM) is attracting attention now. As the MRAM, a device that generates a magnetic wall inside a ferromagnetic body and moves the magnetic wall to operate is now under examination.
It has been now observed that as described in, for example, Non-Patent Document 1 and Non-Patent Document 2, a magnetic wall in a ferromagnetic body is moved by a current and further moved in a direction opposite to the direction of the current. Further, a magnetoresistive effect element that moves a magnetic wall using such a spin torque to perform writing has been described in Patent Document 1. Also, a method described in Patent Document 2 has been examined as a method of introducing such a magnetic wall in the ferromagnetic body. A magnetic memory described in Patent Document 2 has a write wiring for applying an external magnetic field to the ferromagnetic body. In this magnetic memory, writing has been performed by the external magnetic field from the write wiring. Further, there has been described in Patent Document 3 that a base layer is provided below a data storage layer being a ferromagnetic body to realize satisfactory vertical magnetic anisotropy of the data storage layer.